Presentation on theme: "PEST CONTROL IN AGRICULTURE"— Presentation transcript:
1 PEST CONTROL IN AGRICULTURE Crop ProtectionDr. Hadass Cohen
2Course DescriptionThis course provides an holistic view on pest management, emphasizing the integration of different methods for maintaining pests, diseases and weeds below damaging levels, with the goal of minimizing the use of chemical pesticides that disrupt the environment.
3Course Objectives Introduction: A short review on different approaches to pest management
4Course Objectives 2.Integrated Pest Management (IPM),principles. 3. IPM applications: Apple orchard program for the control of: insects, arthropods & diseases.4. Cotton program for the control of weeds & insects.5. Greenhouse latest engineering and their impact on crop protection.6. Natural fertilizers.
5The course concludes with a visit in an R&D facility, demonstrating some practices of IPM in fruit & vegetables.
6Introduction:A short review on different approachesto pest management
8Pest Control Methods Cultural Mechanical Physical Chemical Biological Genetic Engineering of Plants
9Intensive FarmingIntensive farming is an agricultural system that aims to get maximum yield from the available land. Under this technique, food is produced in large quantities with the help of chemical fertilizers and pesticides that are appropriately used to save such agricultural land from pests and crop diseases
10Intensive Farming - Advantages Aids in solving the worldwide hunger problems to a great extent, contributes towards meeting the ever-growing demand for food supplies.It is cost effective, common people can afford a balanced and nutritious dietIntensive Farming - Advantages
11Intensive Farming - Advantages Have enabled a substantial increase in production. in contrast to many sorts of sustainable agriculture such as organic farming or extensive agriculture
12Impacts of Intensive Farming on Soil Soil erosion from farmland threatens the productivity of agricultural fields.The sub soils that remain tend to be:less fertileless absorbent,less able to retain pesticidesless able to retain fertilizersless able to retain plant nutrients.
13Impacts of Intensive Farming on Water Increasing erosion and poisoningwater with agricultural chemicals.
14Impacts of Intensive Farming - Example Cucumber growers in theSharon region, Israel,have been growing the same cropfor the last 3 decades.Plant protection problems have aroused:Decline of nutrients in soilAttack of new viruses, diseases & pestsResistance to pesticides
15Impacts of Intensive Farming on Livestock Involve very large numbers of animals raised on limited land which require large amounts of food, water and medical inputs, causes:PollutionVarious diseasesInfectionsPoor hygiene
16Cultural Control in Intensive Farming Crop RotationIntercroppingPhonological AsynchronySanitationManaged ApplicationResistant VarietiesTrap Crops
17Crop RotationIntensive grazing affects animal health Crop rotation may contribute to overcome pest attacksExamplePasture rotation hadeliminated cattle fever, insouthern U.S., by avoiding thetransmission of the disease bycattle ticks, Boophilus annulatus.
18IntercroppingMay increase environmental diversity or abundance of natural enemies, such as predator spiders or parasitic waspsExampleInter-planted plants act as afood source or breedingground for beneficial insects as they search out for pests.
19Phonological Asynchrony Altering the time of year for planting or harvesting.ExampleSweet corn can escape most injury from corn earworms (Helicoverpa zea) if it is planted in early spring and harvested before larvae mature.
20Sanitation Removing crop debris Example Removing crop debris from cotton fields after harvest eliminates overwintering populations of pink bollworms. (Pectinophora gossypiella)
21Managed ApplicationManaged application of water or fertilizer can have a big impact on the survival of pest populations.ExampleRegular rainfall (or overheadirrigation) can significantlyreduce infestations oftwospotted spider mites(Tetranychus urticae) in tree fruits.
22Plant Resistant Varieties Selection of plant resistant varietiesExampleGrowing resistant varietiesof wheat for reducing severity ofwheat stem sawfly
23Trap Crops French Marigold protect vegetables from nematodes. The idea is to lure certain pests away from the target crop onto the trap crops which then need to be removed once they are infected. ExampleFrench Marigold protectvegetables from nematodes.
24Cultivation Exclusion using screens or barriers Trapping Mechanical ControlCultivationExclusion using screens or barriersTrapping
25CultivationExampleClean tillage between field rotations, or remove weeds by hand (home gardener, organic grower or researchers) , decreases the establishment of new weeds.
26Exclusion Exclusion by using screens or barriers Example Banding trees with Tangle foot tocontrol cankerworms.
27Trapping (suction devices, collecting machines) ExampleMass trapping of tea mosquito bugs with yellow sticky traps loaded with pheromone.
28Physical Control Heat Burning surface residues, soil pasteurization. ExampleBurning surface residues, soil pasteurization.ColdCold storage of potatoes to prevent storage rot.
30Chemicals – Conventional Pesticides, Grouped According to Target Organism InsecticidesHerbicidesFungicidesRodenticidsAcaracides(miticides)Molluscicides (snail control)Antimicrobials / biocidesMicrobial pesticides
31Chemicals – Conventional Pesticides Types of pesticides – With Relation to Habitat Narrow-spectrum /broad-spectrumTargeted organisms -no harm to non-targetKills a variety of organisms in addition to pest
32First Generation Pesticides Historically Used Pesticides Inorganic compounds (minerals)–Lead–Mercury–ArsenicBotanicals–Nicotine–Pyrethrum–Rotenone
33Second Generation Pesticides, Synthetic Dichloro-diphenyl-trichloroethane(DDT) Synthesized in 1873Insecticidal properties –Paul Müller, 1939 (Nobel Prize) used to control body liceWidespread useBanned in US in 1972Currently there are thousands of synthetic pesticide products, made up of more than 1,000 different chemicals and combinations,not as environmentally, persistent as DDT
34DDT is a powerful insecticide DDT is a powerful insecticide. It binds to the voltage-gated sodium channel and locks it in the open state. Prolonged influx of sodium ions causes the nerves to fire repeatedly and this causes death of the insect
35DDT is Blamed Causing the Decline of the Bald Eagle Population Unfortunately, even though DDT is not immediately toxic to other animals it does have one disadvantage: it is extremely stable—its biological half-life is about eight years. Furthermore, DDT is stored in fatty tissues and its buildup in birds and fish resulted in considerable loss of these species. That, coupled with the evolution of DDT resistant insects, led to a ban of DDT in most countries by the 1970's
36Synthetic Insecticides: Modes of Action (1) Organochlorines & PyrethroidsRetards closure of ion channel in CNS, results in repetitive spontaneous nervous discharges.(DDT, aldrin, dieldrin, chlordane) (fenvalerate, permethrin)Organophosphates & Carbomates*Binds to hydroxyl group to inhibit formation of acetyl- cholinesterase.(Malathion, diazinon, methylparathion)(Carbaryl, carbofuran, methiocarb)* Insect growth regulators (fenoxycarb)
38Synthetic Insecticides: Modes of Action (2)NeonicotinoidsAct selectively on insect nicotinic acetylcholine receptors.(imidacloprid, thiacloprid, spinosad )BiologicalsComplex of various modes and sites.(Bt, abamectin, carpo-virus)Semiochemicals(synthetic sex pheromones, attract & kill strategy).
39Synthetic Insecticides: Modes of Action (3)Growth & DevelopmentChitin Synthetic InhibitorsChitin synthesis inhibitors (cyromazine, diflubenzuron)Insect Growth RegulatorsEcdison agonist, causing the insect to unable to molt. (tebufenozide, halofenozide)Juvenile hormone mimic, interfering in the insects metamorphoses(hydroprene, methoprene)
40Synthetic Insecticides: Modes of Action (4)Metabolic/Energy processes + BotanicalsOxidative phosphorylation disruptor – inhibitor(fenbutatin oxide, cyhexatin, pymetrozine)Horticultural oilsMechanical suffocation by blocking breathing or disruption of cellular membranesNontoxic attack , feeding barrier (kaolin – repellent)Electron transport inhibitor (rotenone - botanical)
41Synthetic Insecticides: Advantages Protecting cultivated crops from most pest invasionsCost effectiveMarking a major advance in crop protection, replacing the inferior pesticides based on metallic salts
42Synthetic Insecticides: Disadvantages Ecological and Medical Problems Chemicals lace the food with residuesEstimation: Only 0.1% of the chemicals used in crop protection reach the target pestHealth risks associated with conventional pesticide residues in foods are well-established and subject to intensive regulatory efforts aimed at reducing exposure99.9% of chemicals, enter the environment to cause hazards to non-target organisms including humans
43.Global demand for fertilizer nutrients (a) & pesticide active ingredients (b),
44.Global demand shares by region for fertilizer nutrients (a) & pesticide active ingredients (b), 2010
45Global Use of Pesticides There are currently more than 1,600 pesticides available and about 4.4 million tons used annually, at a cost of more than $20 billion. The United States accounts for more than 25 percent of this market.
47Types of Natural Enemies ParasitoidsPathogensPredatorsWeed Feeders
48Parasitoids Major characteristics of insect parasitoids: Specialized in their choice of hostSmaller than host only the female searches for hostDifferent parasitoid species can attack different life stagesof hostEggs or larvae are usually laid in, on, or near hostImmature remain on or in host; adults are free-living,mobile, and may be predaceousImmature almost always kill host
49Entomoparasitoids Example Trichogramma nubilale wasp Trichogramma lay their eggs inside the eggs of cornborers and other moths. When theTrichogramma hatch, they begin to eat thedeveloping caterpillar inside the egg.
50PathogensMajor characteristics of insect pathogens:Kill or reduce reproduction, slow growth, or shorten the lifeof pests.Usually specific to target species or to specific life stages.Effectiveness may depend on environmental conditions orhost abundance.Degree of control may be unpredictable.Relatively slow acting (several days) to provide adequatecontrol.
51EntoemopathogenExample Verticillium lecanii produces a cyclodepsipeptide toxin called bassianolide, which has been shown to kill silkworm. The fungus produces other insecticidal toxins such as dipicolinic acid. The activity of V. lecanii depends on the strain of the fungus. V. lecanii strains with small spores infect aphids, whereas, fungal strains with large spores infect whiteflies.
53PredatorsMajor characteristics of arthropod predators:Adults and immature are often generalists rather than specialistsGenerally are larger than their preyKill or consume many preyAttack immature and adult prey
54Predatory beetles Example Cryptolaemus montrouzieri feeds on mealy bug Beetles lay eggs directly into mealybug eggsacs. Larvae grow to 13 mm long and arecovered in waxy filaments closelyresemble their mealybug prey. All stagesare predatory on mealybugs. The youngpredacious larva sucks out the bodycontents of its mealybug prey, passingthrough four instars before pupating onnearby. supports.
55Weed-Feeding Natural Enemies Insects - can control weeds by feeding on seeds, flowers, leaves, stems, roots, or combinations of these, or by transmitting plant pathogens, which will infect plants.Other natural enemies of weeds include plant pathogens: nematodes ,vertebrates , fungi
56Weed-Feeding Fungi Example The fungus Colletotrichum gloeosporioides f. sp. Aeschynomene, causes an anthracnose on Aeschynomene virginica and has been used as a biological control agent to control this weed in the U.S. Aeschynomene is known as a noxious weed which infests rice and soybean fields in North America.
57Biological Control , Advantages 1. It poses little threat to non-target organisms2. Once established, biological control agents are selfperpetuating and can spread on their own, while othercontrol methods require action or inputs periodically3. The environmental impact is generally low4. The pest is unable (or very slow) to develop a resistance.
58Biolagical Control, Disadvantages 1. Control is slow.2. Density dependent.3. It will not exterminate the pest.4. It is often unpredictable.5. It is difficult and expensive to develop and supply.6. It requires expert supervision.
59Plant Resistance Plant disease induced resistance Plant resistance to insects (genetic engineering)Plant resistance and tolerance to nematodes
60Plant Disease Resistance Plant disease resistance derives both from pre-formed defenses and from infection-induced responses mediated by the plant immune system
61Plant Resistance to Nematodes Resistance to some species of Meloidogyne in beans (large lima), cowpeas, sweet potatoes, and tomatoes are the only cases where plant resistance is currently used as a nematode management tactic. Resistant cultivars, especially of sweet potatoes and tomatoes, have been used mostly in conjunction with a preplant fumigation treatment.
62Genetic Engineering of Plants Most genetically modified organisms (GMOs) are altered to be herbicide-resistant (over 70% of all GMOs), others include insect - resistant .ExampleTransgenic Bt corn, cotton potato, tomato and rice are grown instead of Bt spray usage. The most common grown one is Bt cotton.
63Insect-Resistant - Advantages Economic benefits - crop yields are saved from loss to insect pests and money is saved by not applying insecticides that would have been applied to susceptible varieties.Ecological and environmental benefits - increases in species diversity in the agro-ecosystem, in part because of reduced use of insecticides, far less polluted and detrimental to natural resources.
64Genetic Engineering of Pest SIT – Sterile Insect TechniqueExampleThe sterile insect technique (SIT) is used to control fruit fly pests of economic significance, throughout the world